Many conventional buttons, sliders, dials, and other controls provide tactile or haptic feedback to the user. Feedback may be provided to the user by mechanical elements, such as detents, which are fabricated into the device. The feedback provided by devices relying primarily or solely on mechanical elements is rarely variable and, if variable, is not controllable in real time and hence is not programmable.
Some conventional controls comprise active or resistive (also referred to as passive) feedback, which is controllable in real time, see, e.g., U.S. Pat. No. 5,220,260. The addition of controllable haptic feedback to a device normally requires an actuator, and the actuator requires a power source. In devices designed for low power consumption, such as cell phones and other handheld devices, the power necessary to supply the actuator may be difficult to provide.
Thus, a need exists for systems and methods for providing controllable haptic feedback while minimizing power requirements.